1. Field of Invention
The present invention relates to a thin film solar cell and a manufacturing method thereof, and more generally to a thin film solar cell having a passivation layer and a manufacturing method thereof.
2. Description of Related Art
With the raise of the consciousness of environmental protection, the concept of energy saving and carbon dioxide reduction has gradually drawn attention, and the development and utilization of renewable energy have become the focus in the world. A solar cell which converts solar light into electricity is the most promising in energy industry nowadays, so that manufacturers devote themselves to the manufacturing of the solar cell. Currently, the key issue of the solar cell is the improvement of the photoelectric conversion efficiency thereof. Therefore, to improve the photoelectric conversion efficiency of the solar cell means enhancing the product competitiveness.
FIG. 1 schematically illustrates a cross-sectional view of a conventional thin film solar cell. A thin film solar cell 100 includes a substrate 110, a first conductive layer 120, a photoelectric layer 130 and a second conductive layer 140. The thin film solar cell 100 has a plurality of photovoltaic elements 102 connected in series. The photoelectric conversion layer 130 is a photoelectric conversion structure having a PIN junction.
For example, when a light L enters the thin film solar cell 100 from outside, electron-hole pairs are generated in the photoelectric conversion layer 130 by the solar energy, and the internal electric field formed by the PIN junction makes electrons and holes respectively move toward the first conductive layer 120 and the second conductive layer 140, so as to generate a storage state of electricity. Meanwhile, if a load circuit or an electronic device is connected, the electricity can be provided to drive the circuit or device.
However, in the thin film solar cell 100, the surface recombination of the electron-hole pairs easily occurs near the interface S between the second conductive layer 140 and the photoelectric conversion layer 130, and thus, the photoelectric conversion efficiency of the thin film solar cell 100 is affected.